Color conversion panel and display device including the same

ABSTRACT

A color conversion display panel includes a substrate. A color conversion portion is disposed on the substrate. The color conversion portion includes a semiconductor nanocrystal. A transmission portion is disposed on the substrate. A blue light blocking filter is disposed between the substrate and the color conversion portion. The blue light blocking filter includes a first convex portion that protrudes toward the substrate. The transmission portion includes a first region including a scatterer and a second region including a second convex portion that protrudes toward the substrate.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of co-pending U.S. patent applicationSer. No. 16/541,282, filed on Aug. 15, 2019, which is a Continuation ofU.S. patent application Ser. No. 15/870,053, filed on Jan. 12, 2018,Which claims priority to and the benefit of Korean Patent ApplicationNo. 10-2017-0097724 filed in the Korean Intellectual Property Office onAug. 1, 2017, the entire contents of which are herein incorporated byreference.

TECHNICAL FIELD

The present disclosure relates to a display device and, morespecifically, to a color conversion display panel and a display deviceincluding the same.

DISCUSSION OF THE RELATED ART

A liquid crystal display device may include two field generatingelectrodes, a liquid crystal layer, a color filter, and a polarizationlayer. Light emitted from a light source reaches a viewer through theliquid crystal layer, the color filter, and the polarization layer.Light loss may occur in the polarizing layer, the color filter, or theother various layers of the display device. Similarly, light loss mayoccur in other forms of display devices such as an organic lightemitting diode display.

Some forms of display devices include a color conversion display panel.Color conversion display panels may use semiconductor nanocrystals, suchas quantum dots, to provide the display device with high colorreproducibility and reduced light loss generated in a polarization layeror a color filter.

SUMMARY

A color conversion display panel includes a substrate. A colorconversion portion is disposed on the substrate. The color conversionportion includes a semiconductor nanocrystal. A transmission portion isdisposed on the substrate. A blue light blocking filter is disposedbetween the substrate and the color conversion portion. The blue lightblocking filter includes a first convex portion that protrudes towardthe substrate. The transmission portion includes a first regionincluding a scatterer and a second region including a second convexportion that protrudes toward the substrate.

A color conversion display panel includes a substrate having a firstsurface and a second surface opposite to the first surface. A colorconversion portion is disposed on the first surface of the substrate.The color conversion portion includes a semiconductor nanocrystal. Atransmission portion is disposed on the first surface of the substrate.The substrate includes a plurality of convex portions in the secondsurface.

A display device includes a lower display panel including a plurality ofthin film transistors. A color conversion display panel at leastpartially overlaps the lower display panel. A liquid crystal layer isdisposed between the lower display panel and the color conversiondisplay panel. The color conversion display panel includes a substrate.A color conversion portion including a semiconductor nanocrystal isdisposed between the substrate and the liquid crystal layer. Atransmission portion is disposed between the substrate and the liquidcrystal layer. A blue light blocking filter is disposed between thesubstrate and the color conversion portion, and includes a convexportion that protrudes toward the substrate. The transmission portionincludes a first region including a first scatterer and a second regionincluding a second scatterer and a convex portion that protrudes towardthe substrate. A volume fraction of the first scatterer included in thefirst region is greater than a volume fraction of the second scattererincluded in the second region.

A display device includes a lower display panel including a plurality ofthin film transistors. A color conversion display panel at leastpartially overlaps the lower display panel. A liquid crystal layer isdisposed between the lower display panel and the color conversiondisplay panel. The color conversion display panel includes a substrate.A color conversion portion including a semiconductor nanocrystal isdisposed between the substrate and the liquid crystal layer. Atransmission portion is disposed between the substrate and the liquidcrystal layer. A blue light blocking filter is disposed between thesubstrate and the color conversion portion, and includes a convexportion that protrudes toward the substrate. The transmission portionincludes a first region including a scatterer and a second regionincluding a convex portion that protrudes toward the substrate. Thesecond region does not include the scatterer.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the present disclosure and many of theattendant aspects thereof will be readily obtained as the same becomesbetter understood by reference to the following detailed descriptionwhen considered in connection with the accompanying drawings, wherein:

FIG. 1 is a top plan view illustrating pixels of a display deviceaccording to an exemplary embodiment of the present invention;

FIG. 2 is a cross-sectional view taken along a line II-II′ of FIG. 1according to an exemplary embodiment of the present invention;

FIG. 3 is a cross-sectional view taken along a line II-II′ of FIG. 1according to an exemplary embodiment of the present invention;

FIG. 4 is a cross-sectional view taken along a line II-II′ of FIG. 1according to an exemplary embodiment of the present invention;

FIG. 5 is a cross-sectional view taken along a line II-II′ of FIG. 1according to an exemplary embodiment of the present invention;

FIG. 6 is a cross-sectional view taken along a line II-II′ of FIG. 1according to an exemplary embodiment of the present invention; and

FIG. 7 is a cross-sectional view taken along a line II-II′ of FIG. 1according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In describing exemplary embodiments of the present disclosureillustrated in the drawings, specific terminology is employed for sakeof clarity. However, the present disclosure is not intended to belimited to the specific terminology so selected, and it is to beunderstood that each specific element includes all technical equivalentswhich operate in a similar manner.

In the figures and the description thereof, like numerals may refer tolike or similar elements.

In the drawings, the size and thickness of layers, films, panels,regions, etc., may be exaggerated for clarity.

It will be understood that when an element such as a layer, film,region, or substrate is referred to as being “on” another element, itcan be directly on the other element or intervening elements may also bepresent.

Further, in the specification, the phrase “in a plan view” may mean thatan object portion is viewed from above, and the phrase “in across-section” may mean that an object is viewed from a side though byvertically cutting the object.

Hereinafter, a color conversion display panel and a display deviceincluding the same, in accordance with an exemplary embodiment of thepresent invention, will be described with reference to FIG. 1 and FIG.2. FIG. 1 is a top plan view illustrating pixels of a display device isaccording to an exemplary embodiment of the present invention, and FIG.2 is a cross-sectional view taken along a line II-II′ of FIG. 1.

The display device, according, to an exemplary embodiment of the presentinvention, may include a light unit 500 (e.g. a backlight), a lowerdisplay panel 100, a color conversion display panel 30, and a liquidcrystal layer 3 disposed between the lower display panel 100 and thecolor conversion display panel 30.

The light unit 500 may include a light source for generating lighthaving a first wavelength, and a light guide for receiving the lightgenerated from the light source and guiding the light towards the lowerdisplay panel 100 and the color conversion display panel 30. The firstwavelength may be in a range of about 400 nm to about 500 nm, or may bein a range of about 420 nm to about 480 nm. The light source may emitblue light. For example, the light source may be a blue light emittingdiode (LED).

A light unit including a white light source or an ultraviolet lightsource may be used instead of the light unit 500 including theabove-described blue light source. Hereinafter, the display device usingthe light unit 500 including the blue light source will be described.

The lower display panel 100 includes a plurality of transistors, and thelower display panel 100 at least partially overlaps the color conversiondisplay panel 30. The liquid crystal layer 3 includes a plurality ofliquid crystal molecules 31.

According to an exemplary embodiment of the present invention, thedisplay device may include a first polarization layer 12 disposedbetween a first substrate 110 and the light unit 500. The firstpolarization layer 12 may linearly polarize the light generated in thelight unit 500.

A coated polarization layer, a film polarization layer, a wire gridpolarizer, or the like may be used as the first polarization layer 12.The first polarization layer 12 may be disposed on a surface of thefirst substrate 110 in various ways, for example, by being attached as afilm, formed as a coating, or formed through printing.

The lower display panel 100 includes a gate line 121 that extends in afirst direction. The lower display panel 100 further includes a gateelectrode 124, a gate insulating layer 140 disposed on the gate line121, and a semiconductor layer 154 disposed on the gate insulating layer140. A data line 171 is disposed on the gate insulating layer 140. Thedata line 171 extends in a second direction and is connected with asource electrode 173. A drain electrode 175 is disposed in a same layeras the source electrode 173. A passivation layer 180 is disposed on thedata line 171 and the drain electrode 175.

The semiconductor layer 154 is disposed on the gate electrode 124 andmay include a channel between the source electrode 173 and the drainelectrode 175. The gate electrode 124, the semiconductor layer 154, thesource electrode 173, and the drain electrode 175 may togetherconstitute one transistor Tr.

A pixel electrode 191 and a first alignment layer 11 are sequentiallydisposed on the passivation layer 180. The pixel electrode 191 iselectrically connected to the drain electrode 175 through a contact hole185 of the passivation layer 180.

The pixel electrode 191 may be disposed in a matrix form, and the pixelelectrode 191 may have various shapes. Although the pixel electrode 191is illustrated as having a planar shape, the pixel electrode 191 mayhave other shapes such as a slit-shaped pixel electrode.

The color conversion display panel 30 includes a second substrate 310that at least partially overlaps the first substrate 110. A lightblocking member 320 may be disposed between the second substrate 310 andthe lower display panel 100.

The light blocking member 320 is disposed between a first colorconversion portion 330R and a second color conversion portion 330G,between the second color conversion portion 330E and a transmissionportion 330B, and between the transmission portion 330B and the firstcolor conversion portion 330. The light blocking member 320 may define aregion in which the first color conversion portion 330R, the secondcolor conversion portion 330G, and the transmission portion 330B aredisposed.

The light blocking member 320 may include a material that absorbsincident light or a material that reflects light. For example, a lightblocking member 320 including a metal material may increase lighttransmission efficiency by reflecting light introduced from the firstcolor conversion portion 330R, the second color conversion portion 330G,and the transmission portion 330B toward the first color conversionportion 330R the second color conversion portion 330G, and thetransmission portion 330B, respectively.

A first passivation layer 321 may be disposed between the light blockingmember 320 and the color conversion portions 330R and 330G, and betweenthe light blocking member 320 and the transmission portion 330B. Thefirst passivation layer 321 may at least partially overlap a frontsurface of the second substrate 310.

The first passivation layer 321 may include a material having a lowerrefractive index than those of the second substrate 310, the blue lightblocking filter 325, and the transmission portion 330B. For example, therefractive index of the second substrate 310 may be about 1.5, and therefractive indexes of the transmission portion 330B and the blue lightblocking filter 325 may each be about 1.7. According to an exemplaryembodiment of the present invention, the refractive index of the firstpassivation layer 321 may be about 1.2.

The first passivation layer 321 may have a surface that faces the liquidcrystal layer 3, and the surface may include a plurality of recessportions 321 a. The recess portions 321 a may be regularly arranged at aconstant distance.

According to an exemplary embodiment of the present invention, onerecess portion 321 a may be positioned to at least partially overlap onepixel, but the present specification is not limited thereto. Inaddition, recess portions 321 a disposed adjacently may either beconnected to each other, or may be spaced apart from each other. Therecess portions 321 a may have a constant curvature, such as a semisphere, as is illustrated herein, or the recess portions 321 a may havean irregular curvature.

In general, where a light is introduced from a first material having arelatively large refractive index into a second material having arelatively small refractive index, the light may be totally reflected atan interface between the first material and the second material when anincidence angle of the light is greater than a particular angle. Lightpassing through the transmission portion 330B or the blue light blockingfilter 325 is introduced into the first passivation layer 321. In thiscase, the transmission portion 330B or the blue light blocking filter325 has a refractive index that is greater than that of the firstpassivation layer 321. Accordingly, total reflection may occur for lightthat is introduced at a critical angle, as a minimum.

According to exemplary embodiments of the present invention, the firstpassivation layer 321 includes the recess portions 321 a at theinterface. The recess portions 321 a may vary an incidence angle oflight introduced to the interface to reduce total reflection occurringat the interface. Since an amount of light emitted to the outside of thesecond substrate 310 increases as the total reflection decreases,light-emitting efficiency of the display device may increase.

A blue light blocking filter 325 may be disposed between the firstpassivation layer 321 and the first color conversion portion 330R, andbetween the first passivation layer 321 and the second color conversionportion 330G. The blue light blocking filter 325 may be disposed only inregions for emitting red and green light and not in a region foremitting blue light.

The blue light blocking filter 325 may include a plurality of convexportions 325 a which face the second substrate 310. The convex portions325 a may be regularly arranged at a constant distance.

The convex portion 325 a of the blue light blocking filter 325 and therecess portion 321 a of the first passivation layer 321 may havecomplementary shapes. The present specification has described theexemplary embodiment in which the blue light blocking filter 325includes the convex onion 325 a. However, a shape of the convex portion325 a included in the blue light blocking filter 325 may be changeddepending on a shape of the recess portion 321 a included in the firstpassivation layer 321.

Similar to the recess portions 321 a, one convex portion 325 a may bedisposed to correspond to one pixel. In addition, the convex portions325 a disposed adjacently may be connected to each other, or may bespaced apart from each other. Further, although the presentspecification has described the convex portions 325 a having a constantcurvature, the convex portions 325 a may have an irregular curvature.

The blue light blocking filter 325 may block or absorb blue lightemitted from the light unit 500. Blue light from the light unit 500 isconverted into red or green light by a semiconductor nanocrystal. Inthis case, some of the blue light may be emitted through the secondsubstrate 310 without being converted. The blue light blocking filter325 may have a single-layer structure or a stacked structure of aplurality of layers to prevent the emission of unconverted blue light.

The blue light blocking filter 325 may include any material forperforming the above-mentioned effects, and may include a yellow colorfilter as an example. A refractive index of the blue light blockingfilter 325 including the yellow color filter may be about 1.7, and itmay have a refractive index that is greater than that of the firstpassivation layer 321.

Light is totally reflected at an interface between the blue lightblocking filter 325 having a large refractive index and the firstpassivation layer 321 having a small refractive index when an incidenceangle is greater than a certain angle in a case where the light isintroduced from the blue is light blocking filter 325 into the firstpassivation layer 321. However, the color conversion display panel 30,according to an exemplary embodiment of the present invention, mayinclude an irregular pattern formed between the first passivation layer321 and the blue light blocking filter 325, thereby changing anincidence angle of light to reduce the total reflection occurring at theinterface.

The first color conversion portion 330R and the second color conversionportion 3300 may be disposed between the blue light blocking filter 325and the liquid crystal layer 3, and the transmission portion 330Bincluding a first region 330B_1 and a second region 330B_2 may bedisposed between the second substrate 310 and the lower display panel100.

The first color conversion portion 330R may include a firstsemiconductor nanocrystal 331R The second color conversion portion 330Gmay include a second semiconductor nanocrystal 331G. Light introducedinto the first color conversion portion 330R may be converted into redlight by the first semiconductor nanocrystal 331R, and may then beemitted from the first color conversion portion 330R. Light introducedinto the second color conversion portion 330G may be converted intogreen light by the second semiconductor nanocrystal 331G, and may thenbe emitted from the second color conversion portion 330G.

The first semiconductor nanocrystal 331R may include a red phosphorand/or a red quantum dot for converting the introduced blue light intored light. The second semiconductor nanocrystal 331G may include a greenphosphor and/or a green quantum dot for converting the introduced bluelight into green light.

The red quantum dot and the green quantum dot may be selected from agroup II-VI compound, a group III-V compound, a group IV-VI compound, agroup IV element, a group IV compound, and a combination thereof.

For the group II-VI compound, a binary compound selected from CdSe,CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, and a mixturethereof; a ternary compound selected from CdSeS, CdSeTe, CdSTe, ZnSeS,ZnSeTe, ZnSTe, HgSeS, HgSeTe, CdZnS CdZnSe, CdZnTe, CdHgS, CdHgSe,CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, and a mixture thereof; ora quaternary compound selected from HgZnTeS CdZnSeS, CdZnSeTe, CdZnSTe,CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, and a mixturethereof, may be employed. For the group III-V compound, a binarycompound selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN,InP, InAs, InSb, and a mixture thereof; a ternary compound selected fromGaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb,InNP, InNAs, InNSb, InPAs, InPSb, and a mixture thereof; or a quaternarycompound selected from GaAlNAs GaAlNSb, GaAlPAs, GaAlPSb, GaInNP,GaInNAs, GaInNSb, GaInPAs, GaInPSb, GaAlNP, InAlNP, InAlNAs, InAlNSb,InAlPAs, InAlPSb, and a mixture thereof, may be employed. For the groupIV-VI compound, a binary compound selected from SnS, SnSe, SnTe, PbS,PbSe, PbTe, and a mixture thereof; a ternary compound selected fromSnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe SnPbSTe, and amixture thereof; or a quaternary compound selected from SnPbSSe,SnPbSeTe, SnPbSTe, and a mixture thereof, may be employed. For the IVgroup element, Si, Ge, or a mixture thereof may be selected. For the IVgroup compound, a binary compound selected from SiC, SiGe, and a mixturethereof may be employed.

In this case, the binary compound, the ternary compound, or thequaternary compound may exist in a uniform concentration or in apartially different concentration in particles.

The quantum dot may include multiple quantum dots, and each of thequantum dots may have a core/shell structure in which one quantum dot(shell) surrounds another quantum dot (core). An interface between acore and a shell may have a concentration gradient such that aconcentration of an element in the shell decreases toward a centerthereof.

The quantum dot may have a full width at half maximum (FWHM) of thelight-emitting wavelength spectrum that is equal to or less than about45 nm, preferably equal to or less than about 40 nm, and more preferablyequal to or less than about 30 nm, and in this range, color purity orcolor reproducibility may be increased. In addition, since light emittedthrough the quantum dot is emitted in all directions, a viewing angle oflight may be increased.

The quantum dot may have various shapes known in the art, for example,the quantum dot may have a shape such as a nanoparticle having aspherical shape, a pyramid shape, a multi-arm shape, or a cubic shape,or may be a nanotube, a nanowire, a nanofiber, a planar nanoparticle,etc.

The red phosphor may include at least one of (Ca, Sr, Ba)S, (Ca, Sr,Ba)₂Si₅N₈, CaAlSiN₃, CaMoO₄, and Eu₂Si₅N₈, but other phosphors mayalternatively be used.

The green phosphor may include at least one of yttrium aluminum garnet(YAG). (Ca, Sr, Ba)₂SiO₄, SrGa₂S₄, barium magnesium aluminate (BAM),α-SiAlON, β-SiAlON, Ca₃Sc₂Si₃O₁₂, Tb3Al₅O₁₂, BaSiO4, CaAlSiON, and(Sr1-xBax)Si₂O₂N₂. In this case, the x may be a number is between 0 and1.

The transmission portion 330B may include the first region 330B_1adjacent to the liquid crystal layer 3 and the second region 330B_2adjacent to the first passivation layer 321.

The second region 330B_2 may include a convex portion 330B_2 acorresponding to the recess portion 321 a of the first passivation layer321, similar to the aforementioned blue light blocking filter 325. Thesecond region 330B_2 may include a convex portion 330B_2 a which facesthe second substrate 310. Total reflection of light may be reduced at aninterface between the second region 330B_2 and the first passivationlayer 321, and an amount of light emitted to the outside of the secondsubstrate 310 may increase.

The transmission portion 330B may allow light emitted from the lightunit 500 and introduced into the transmission portion 330B to passtherethrough. The transmission portion 330B may include a polymermaterial that allows blue light supplied from the light unit 500 to passtherethrough. The transmission portion 330B disposed in a region foremitting blue light may pass the introduced blue light without aseparate phosphor or quantum dot.

According to exemplary embodiments of the present invention, the firstregion 330B_1 may include a scatterer 332, and the second region 330B_2might not include the scatterer 332. The scatterer 332 may scatter lightintroduced into the first region 330B_1 of the transmission portion 330Bso as to increase an amount of emitted light or make front luminance andside luminance more uniform. For example, the scatterer 332 may includeat least one of TiO₂, Al₂O₃, and SiO₂, or an alternative scatteringmaterial. According to exemplary embodiments of the present invention,the second region 330B_2 does not include the scatterer 332, therebypreventing light from being returned to the liquid crystal layerimmediately before being emitted. Accordingly, the amount of lightemitted to the outside of the second substrate 310 may be increased. Inaddition according to an exemplary embodiment of the present invention,the first color conversion portion 330R and/or the second colorconversion portion 330G may include the scatterer 332.

According to exemplary embodiments of the present invention, the firstcolor conversion portion 330 R and the second color conversion portion330G may include the scatterer 332 having substantially a same centraldiameter. The scatterer 332 included in the transmission portion 330Bmay have a central diameter that is smaller than those of the firstcolor conversion portion 330R and second color conversion portion 330G.As used herein, “central diameter” indicates an average value ofdiameters of a plurality of scatterers 332 included in the colorconversion portions 330R and 330G or the transmission portion 330B, andthe diameters of the scatterers 332 may achieve a Gaussian distribution.

For example, the first color conversion portion 330R and the secondcolor conversion portion 330G may each include the scatterer 332 havinga central diameter of about 200 to 220 nm, and the transmission portion330B may include the scatterer 332 having a central diameter of about170 to 190 nm. In addition, volume fractions of the scatterers 332included in the first color conversion portion 330R and the second colorconversion portion 330G may be substantially the same, and the volumefraction of the scatterer 332 included in the transmission portion 330Bmay be greater than that of the scatterer 332 included in the firstcolor conversion portion 330R or the second color conversion portion330G. For example, the volume fraction of the scatterer 332 included inthe transmission portion 330B is substantially the same as a sum of thevolume fractions of the first semiconductor nanocrystal 331R of thefirst color conversion portion 330R and the scatterer 332 included inthe first color conversion portion 330R. Alternatively, the volumefraction of the scatterer 332 included in the transmission portion 330Bis substantially the same as a sum of the volume fractions of the secondsemiconductor nanocrystal 331G of the second color conversion portion330G and the scatterer 332 included in the second color conversionportion 330G.

The first region 330B_1 may have a similar composition to the secondregion 330B_2, except for the inclusion of the scatterer 332. FIG. 2illustrates the first region 330B_1 and the second region 330B_2 whichare disposed at different layers, but the present specification is notlimited thereto. For example, they may be provided as one layer.

The transmission portion 330B may further include a blue pigment and/ora dye. The blue pigment and the dye may absorb at least one of red lightand green light included in external light to thereby prevent colorreproducibility deterioration.

A capping layer 340 may be disposed between the first color conversionportion 330R, the second color conversion portion 330G, the transmissionportion 330B, and the liquid crystal layer 3. The capping layer 340 mayoverlap a front surface of the second substrate 310.

The capping layer 340 may increase light-emitting efficiency byreflecting light generated from the first color conversion portion 330Rand the second color conversion portion 330G.

The capping layer 340 may include a plurality of optical filter layers,and the capping layer may have a structure in which layers havingdifferent refractive indexes are alternately arranged along a directionsubstantially perpendicular to the plane of the second substrate 310.The capping layer 340 may be formed by alternately arranging the layershaving different refractive indexes and may include a multi-layerstructure of about 10 to 20 layers, but other configurations may beused. The capping layer 340 may have a structure in which a siliconoxide (SiOx) film and a silicon nitride (SiNy) film are alternatelyarranged, but other configurations may be used. For example, a titaniumoxide, a tantalum oxide, a hafnium oxide, and/or a zirconium oxide maybe used as a material having a relatively high refractive index, andSiCOz may be used as a material having a relatively low refractiveindex. In the SiOx, SiNy, and SiCOz, x, y, and z as factors determiningthe chemical composition ratio may be controlled depending on processconditions when forming the layers.

When a layer of the layers constituting the capping layer 340, which ismost adjacent to the first color conversion portion 330R, the secondcolor conversion portion 330G, and the transmission portion 330B, isformed of a silicon nitride film, the silicon nitride film may serve asa passivation layer. The capping layer 340 may prevent the first colorconversion portion 330R, the second color conversion portion 330G, andthe transmission portion 330B from being damaged during themanufacturing processes. The semiconductor nanocrystals included in thefirst color conversion portion 330R and the second color conversionportion 330G may be damaged or quenched by moisture and high-temperatureprocesses. The silicon nitride film may prevent this problem.

A planarization layer 350 is disposed between the capping layer 340 andthe liquid crystal layer 3. The planarization layer 350 may serve toplanarize a surface of a constituent element disposed between theplanarization layer 350 and the second substrate 310.

A second polarization layer 22 may be disposed between the planarizationlayer 350 and the liquid crystal layer 3. The second polarization layer22 serves to polarize light passing through the light unit 500, thelower display panel 100, and the liquid crystal layer 3.

A coated polarization layer, a film polarization layer, a wire gridpolarizer, or the like may be used as the second polarization layer 22.The second polarization layer 22 may include a metal. The polarizationlayer 22 may include a plurality of bar-like nanopatterns according toan exemplary embodiment of the present invention, and a width of eachnanopattern may be several nanometers.

An insulating layer 360, a common electrode 370, and a second alignmentlayer 21 may be sequentially disposed between the second polarizationlayer 22 and the liquid crystal layer 3.

The insulating layer 360 may isolate the second polarization layer 22made of metal from the common electrode 370. When the secondpolarization layer 22 is not made of metal, the insulating layer 360 maybe omitted.

The common electrode 370 receiving a common voltage may form an electricfield together with the pixel electrode 191. According to some exemplaryembodiments of the present invention, the common electrode 370 may bedisposed in the lower display panel 100.

The second alignment layer 21 may include a same material as the firstalignment layer 11, and may be manufactured through a same process.

The above-described display device can provide light with increasedcolor purity by including the light unit 500 for providing blue lightand the color conversion portions 330R and 330G for emitting red andgreen light therethrough. In addition, since the second polarizationlayer 22 included in the color conversion display panel 30 is relativelythin, e.g. on the order of several nanometers, a path through whichlight passes is short to minimize light distortion.

Further, when total reflection may be reduced by allowing light passingthrough the color conversion portions 330R and 330G and the transmissionportion 330B to pass through a concave or convex interface, the amountof light emitted to the outside of the second substrate 310 mayincrease.

Hereinafter, a display device according to an exemplary embodiment ofthe present invention will be described with reference to FIG. 3 to FIG.7. FIG. 3, FIG. 4, FIG. 5, FIG. 6, and FIG. 7 are cross-sectional viewsthat illustrate a modification of what is illustrated in FIG. 2.

First, referring to FIG. 3, the first color conversion portion 330R andthe second color conversion portion 330G may be disposed between theblue light blocking filter 325 and the liquid crystal layer 3, and thetransmission portion 330B may be disposed between the second substrate310 and the lower display panel 100.

The transmission portion 330B may include a convex portion 330Ba thatfaces the second substrate 310, The convex portion 330Ba included in thetransmission portion 330B may have a complementary shape to that of therecess portion 321 a of the first passivation layer 321.

The present specification has described the exemplary embodiment inwhich the convex portion 330Ba of the transmission portion 330B directlycontacts the recess portion 321 a of the first passivation layer 321,but the present invention is not limited thereto. For example, a bufferlayer or the like may be disposed between the transmission portion 330Band the recess portion 321 a.

The transmission portion 330B may include the scatterer 332, and mayinclude a first region R1 that at least partially overlaps the colorconversion portions 330R and 330G along a first direction and a secondregion R2 including the convex portion 330Ba.

The transmission portion 330B may allow light emitted from the lightunit 500 and introduced into the transmission portion 330B to passtherethrough. The transmission portion 330B may include a polymermaterial that allows blue light supplied from the light unit 500 to passtherethrough. The transmission portion 330B is positioned in a regionfor emitting blue light without a separate phosphor or quantum dot.

The first region R1 and the second region R2 of the transmission portion330B may include the scatterer 332. The scatterer 332 may be disposed ina region where the convex portion 330Ba is disposed. A volume fractionof the scatterer 332 included in the first region R1 may be greater thanthat of the scatterer 332 included in the second region R2. For example,the volume ratio of the scatterer 332 may decrease from the first regionR1 to the second region R2, and the second region R2 might not includethe scatterer 332.

The scatterer 332 may scatter light introduced into the transmissionportion 330B so as to increase an amount of emitted light or make frontluminance and side luminance more uniform.

The description of other constituent elements may be at least similar tothat of the elements described above with reference to FIG. 1 and FIG.2, and thus the description thereof will be omitted hereinafter.

Next, referring to FIG. 4, the second substrate 310 may include aplurality of recess portions 310 a. For example, the recess portions 310a may be disposed in a surface of the second substrate 310 which facesthe liquid crystal layer 3. The recess portions 310 a may be regularlyarranged at a constant distance.

According to an exemplary embodiment of the present invention, onerecess portion 310 a may be disposed to correspond to one pixel, but thepresent specification is not limited thereto. In addition, the recessportions 310 a disposed adjacently may be connected to each other, ormay be spaced apart from each other. Further, although the presentspecification has described the recess portions 310 a having a constantcurvature, the recess portions 310 a may alternatively have an irregularcurvature.

In general, where light is introduced from a first material having arelatively large refractive index to a second material having arelatively small refractive index, light is totally reflected theinterface between the first material and the second material when anincidence angle is greater than a particular angle. Light passingthrough the transmission portion 330B or the blue light blocking filter325 is introduced into the second substrate 310. In this case, thetransmission portion 330B or the blue light blocking filter 325 has arefractive index that is greater than that of the second substrate 310.Accordingly, total reflection may occur for light that is introduced ata critical angle or more at the interface.

According to an exemplary embodiment of the present invention, anincidence angle of light becomes different at an interface of the recessportion 310 a, and thus a total reflection problem caused by arefractive index may be reduced. Light efficiency of the display devicemay be increased by emitting light that is not able to be emitted to theoutside of the second substrate 310 toward a user.

The blue light blocking filter 325 may include a plurality of convexportions 325 a which face the second substrate 310. The convex portions325 a may be regularly arranged at a constant distance.

The convex portion 325 a of the blue light blocking filter 325 and theconvex portion 325 a of the recess portion 310 a may have complementaryshapes. The present specification has described the exemplary embodimentin which the blue light blocking filter 325 includes the convex portion325 a. However, a shape of the convex portion 325 a included in the bluelight blocking filter 325 may be changed depending on a shape of therecess portion 310 a included the second substrate 310.

Similar to the recess portion 310 a, one convex portion 325 a may bedisposed to correspond to one pixel

In addition, the convex portions 325 a disposed adjacently may beconnected to each other, or may be spaced apart from each other.Further, although the present specification has described the convexportions 325 a having a constant curvature, the convex portions 325 amay alternatively have irregular curvatures.

The transmission portion 330B may include a convex portion 330Ba thatfaces the second substrate 310. The convex portion 330Ba included in thetransmission portion 330B may have a shape that meshes with the recessportion 310 a of the second substrate 310. The present specification hasdescribed the exemplary embodiment in which the convex portion 330Ba ofthe transmission portion 330B directly contacts the recess portion 310 aof the second substrate 310, but other arrangements may be used. Forexample, a buffer layer or the like may be disposed between the convexportion 330Ba and the recess portion 310 a.

It is to be understood that to the extent that constituent elements arenot described below, these elements are at least similar in descriptionto corresponding elements that have already been described.

Next, referring to FIG. 5, according to an exemplary embodiment of thepresent invention, the second substrate 310 may include a plurality ofconvex portions 310 a disposed in a second surface of the liquid crystallayer 3 which faces a first surface of the liquid crystal layer 3. Theconvex portions 310 a may be regularly arranged at a constant distance.

According to an exemplary embodiment of the present invention, onerecess portion 310 a may be disposed to correspond to one pixel. Therecess portions 310 a disposed adjacently may be connected to eachother, or may be spaced apart from one another. Further, although thepresent specification has described the recess portion 310 a having aconstant curvature, the recess portion 310 a may alternatively have anirregular curvature.

Light that is introduced from the second substrate 310 having arelatively large refractive index to the air having a relatively smallrefractive index is totally reflected at the interface therebetween whenan incidence angle is greater than a particular angle. However, thecolor conversion display panel 30, according to exemplary embodiments ofthe present invention, may include the convex portions 310 a formed atthe interface between the second substrate 310 and the air, therebychanging an incidence angle of light for the interface to reduce thetotal reflection. The amount of light emitted to the outside of thesubstrate 310 may thereby be increased.

Referring to FIG. 6, the second substrate 310, according to an exemplaryembodiment of the present invention, may include a pattern layer 311disposed in a second surface of the liquid crystal layer 3 which faces afirst surface of the liquid crystal layer 3. The pattern layer 311 mayinclude a plurality of convex portions 311 a. The convex portions 311 amay be regularly arranged at a constant distance.

The pattern layer 311 may be disposed by various manufacturing processessuch as by being patterned after being attached or applied in the formof a film on the second substrate 310. The pattern layer 311 may be anembossing sheet including convex portions 311 a, or may be apolarization layer or an external light absorbing film including theconvex portions 311 a.

The pattern layer 311 may include a transmissive material, and mayinclude a material having, a lower refractive index than the secondsubstrate 310. For example, the refractive index of the second substrate310 may be about 1.5, and the pattern layer 311 may include an organicor inorganic material having a lower refractive index.

When light is introduced from the second substrate 310 having arelatively large refractive index to air having a relatively smallrefractive index, the light is totally reflected at the interface whenan incidence angle is greater than a particular angle. However, thecolor conversion display panel 30, according to an exemplary embodimentof the present invention, may provide a pattern layer 311 disposed at aninterface between the second substrate 310 and the air. The patternlayer may have a refractive index which is between the refractiveindexes of the second substrate 310 and the air, thereby changing anincidence angle of light for the interface to reduce the totalreflection and an amount of light that is totally reflected. The amountof light emitted to the outside of the second substrate 310 may therebybe increased.

Referring to FIG. 7, the pattern layer 311, according to exemplaryembodiments of the present invention, may include a plurality of convexportions 311 a corresponding to one pixel. For example, one pixel mayoverlap at least two convex portions 311 a. While it is described hereinthat one pixel overlaps four convex portions 311 a is the presentinvention is not limited to this particular arrangement. For example,one pixel may overlap any number of convex portions.

Exemplary embodiments described herein are illustrative, and manyvariations can be introduced without departing from the spirit of thedisclosure or from the scope of the appended claims. For example,elements and/or features of different exemplary embodiments may becombined with each other and/or substituted for each other within thescope of this disclosure and appended claims.

What is claimed is:
 1. A color conversion display panel, comprising: asubstrate; and a color conversion portion disposed on the substrate,wherein the color conversion portion includes: a first color conversionportion including a first semiconductor nanocrystal; a second colorconversion portion including a second semiconductor nanocrystal; a firsttransmission portion disposed on the substrate; a high refractive indexlayer comprising a first high refractive index portion and a second highrefractive index portion, wherein the first high refractive indexportion is disposed between the substrate and the first color conversionportion, and the second high refractive index portion is disposedbetween the substrate and the second color conversion portion; a lightblocking member disposed between the first high refractive index portionand the second high refractive index portion, and a low refractive indexlayer disposed between the first high refractive index portion and thesecond high refractive index portion in a horizontal plane that isparallel to the substrate and overlapping the light blocking member. 2.The color conversion display panel of claim 1, further comprising asecond transmission portion disposed between the substrate and the firsttransmission portion, wherein the first transmission portion includes ascatterer and the second transmission portion does not include thescatterer.
 3. The color conversion display panel of claim 2, furthercomprising a capping layer disposed on the first color conversion layer.4. The color conversion display panel of claim 2, wherein the firsttransmission portion and the second transmission portion include a samematerial.
 5. The color conversion display panel of claim 2, wherein thesecond transmission portion includes a polymer material that allows bluelight supplied from the light unit to pass therethrough.
 6. The colorconversion display panel of claim 2, wherein the first high refractiveindex portion, the second high refractive index portion, and the secondtransmission portion are each thicker at their centers than at theiredges.
 7. The color conversion display panel of claim 1, wherein a sizeof a first surface of the first high refractive index portion facing thefirst color conversion portion is larger than a size of a second surfaceof the first high refractive index portion facing the substrate.
 8. Acolor conversion display panel, comprising: a substrate; and a colorconversion portion disposed on the substrate, wherein the colorconversion portion includes: a first color conversion portion includinga first semiconductor nanocrystal; a second color conversion portionincluding a second semiconductor nanocrystal; a first transmissionportion disposed on the substrate; a high refractive index layercomprising a first high refractive index portion and a second highrefractive index portion, wherein the first high refractive indexportion is disposed between the substrate and the first color conversionportion, and the second high refractive index portion is disposedbetween the substrate and the second color conversion portion; a lightblocking member disposed between the first high refractive index portionand the second high refractive index portion, and a low refractive indexlayer disposed between the first high refractive index portion and thesecond high refractive index portion and overlapping the light blockingmember, wherein a refractive index of the substrate is between arefractive index of the first high refractive index portion and arefractive index of the low refractive index portion.
 9. A displaydevice comprising: a display panel including a plurality of thin filmtransistors; and a color conversion display panel at least partiallyoverlapping the display panel, wherein the color conversion displaypanel includes: a substrate; and a color conversion portion disposed onthe substrate, wherein the color conversion portion includes: a firstcolor conversion portion including a first semiconductor nanocrystal; asecond color conversion portion including a second semiconductornanocrystal; a first transmission portion disposed on the substrate; ahigh refractive index layer comprising a first high refractive indexportion and a second high refractive index portion, wherein the firsthigh refractive index portion is disposed between the substrate and thefirst color conversion portion, and the second high refractive indexportion is disposed between the substrate and the second colorconversion portion; a light blocking member disposed between the firsthigh refractive index portion and the second high refractive indexportion, and a low refractive index layer disposed between the firsthigh refractive index portion and the second high refractive indexportion and overlapping the light blocking member, wherein a refractiveindex of the substrate is between a refractive index of the first highrefractive index portion and a refractive index of the low refractiveindex layer.
 10. The display device of claim 9, further comprising acapping layer overlapping the first color conversion layer.
 11. Thedisplay device of claim 9, wherein the first and second high refractiveindex portions include a same material.
 12. The display device of claim9, the second high refractive index portion does not include ascatterer.
 13. The display device of claim 9, wherein a size of a firstsurface of the first high refractive index portion facing the firstcolor conversion portion is larger than a size of a second surface ofthe first high refractive index portion facing the substrate.
 14. Thedisplay device of claim 9, further comprising a second transmissionportion disposed between the substrate and the first transmissionportion, wherein the second transmission portion include a polymermaterial that allows blue light supplied from the light unit to passtherethrough.
 15. The display device of claim 14, wherein the first highrefractive index portion, the second high refractive index portion, andthe second transmission portion each have a rounded surface that bowstoward the substrate.